An injection molding machine provided with a rotary plate that can be mounted with a plurality of molds has conventionally been used as an injection molding machine for a two-color molding formed from a base material and a covering material that covers the base material. This injection molding machine performs injection molding by mounting two types of core-side molds, one for forming the base material portion and one for forming the covering material, and rotating the rotary plate with respect to a cavity-side mold to exchange the core-side molds. Accordingly, two-color molding can be achieved using one molding machine. It should be noted that a vertical injection molding machine is widely used, which is structured such that the rotary shaft of the rotary plate is oriented in the vertical direction and the mold clamping direction is the vertical direction (see Patent Documents 1 to 3, for example).    Patent Document 1: Japanese Patent Application Publication No. JP-A-S61-182914    Patent Document 2: Japanese Patent Application Publication No. JP-A-H06-198528    Patent Document 3: Japanese Patent Application Publication No. JP-A-H06-71690